Performance Reserch Of The Ammonia Nitrogen Elimination Form Power Plant Wastewater Containing Reverse Osmosis Concentrated Water Using Electrolysis Method

Regeneration of waste water of acid and alkali are of high concentration ammonia nitrogen in power plant, total dissolved solids is mainly sodium and chloride ions, and bivalent fouling ion content is very low, so using reverse osmosis technology to recycle the waste water treatment. Fresh waste from reverse osmosis can be recycle, but concentrated water of containing ammonia and sodium chloride cannot acheve the reuse standard.Therefore we need to process reverse osmosis water. In this paper, we use electrolytic method to deal with reverse osmosis concentrated, through electrochemical performance tests to choose the appropriate anode material, at he same time, it is studied the effect of remove ammonia, chlorine, energy consumption, tank pressure and plate scaling effect form electrolysis current density, pH, TDS, anode material, and puts forward prevention measures of plate failure. The following results were achieved.The chlorine and oxygen evolution potentials of four types of metal oxide coated titanium DSA anode are tested using electrochemical experiment. Four kinds of DSA anode material of coating formula respectively different Ti/RuO2-Ir O2(R1 and R2) with different coating formula of Ti/IrO2-Ta2O5(T1 and T2). The results showed that the chlorine evolution potentials of four types of metal oxide coated titanium DSA is between 1100 mVvs.SCE and 1125 mVvs.SCE, with the same as GBT22839-2010 “electrolytic seawater sodium hypochlorite generator technical conditions”; the oxygen evolution potential is between 1240 mVvs.SCE and 1275 Vvs.SCE. This four types of metal oxide coated titanium DSA can be used as analysis of chlorine electrode. Considering technical and economic factors, we should choose low chlorine evolution potential, high oxygen evolution potential and cheaper of Ti/RuO2-IrO2 materials as electrolytic experiment of DSA electrode.Current density have a greater influence on the degradationg of ammonia and oxidation rate, current density in higher, the degradation of ammonia time is shorter, transient oxidation rate of ammonia is higher; ammonia in the process of electrochemical degradation of average energy consumption is relatively high, but not by much. TDS, pH value of the water sample in the process of electrolytic oxidation rate of ammonia, total chlorine concentration change and chlorice ion effect is relatively small; the TDS is lower, the current density is higher, the pH is higher, the degradation of ammonia in the process of electrolytic average relative to the higher emergy consumption, but increase modeslty; when pH is 7.05, it is higher than 9.18 of pH in the average ammonia oxidation rate. But due to the recovery of pure alkali wastewater treatment by reverse osmosis process produced by the strong alkaline water, pH is above 9.0, if the neutral of pH needs to consume a certain amount of hydrochloric acid, so the operation cost will be increased.Two metal oxide coated titanium DSA of Ti/Ru O2-IrO2(R1) and Ti/RuO2-IrO2(R2) are used in electricity and remove ammonia chloride under same working conditions, the results show that the Ti/RuO2-IrO2(R2) is better in addition to ammonia and chlorine system effect; under the condition of different working conditions, as the electrolytic time extended, ammonia concentration of water samples is in a linear decline, and is also gradually reducing the chloride ion concentration, ammonia removal after total chlorine concentration is rapidly rising, the average energy consumption of ammonia are gradually increased, total chlorine is slowly rising up to 2000mg/L at the beginning of the electrolytic in the water samples and after basic remains the same, until after the ammonia is removed completely, total chlorine concentration is rapidly rising, total chlorine concentration will reach about 6000mg/L, when continuing electrolytic in short time. Under the same working condition, high temperature is easier to make harden scale; harden scale has obvious effect on the electric lifting system of ammonia and chlorine. Plate chean degree is higher, the averate energy consumption of ammonia is smaller.In the electrolytic processing, the cell voltage will increase over time; the greater the current density, the bigger the cell voltage; after completely removed ammonia, total chlorine will grow rapidly in a short time.